The authors acknowledge Mrs. Yupaporn Kiatsakulcharoen and Miss Kamolwan Mangkalad, the Center of Excellent for Dental Implantology, Chiang Mai University for clinical assistance, Mr. Aitthiphon Chongchai, the Department of Biochemistry, Faculty of Medicine Chiang Mai University for laboratory assistance, Dr.Thanapat Sastraruji, Faculty of Dentistry, Chiang Mai University for statistical consultation, and Dr. M. Kevin O Carroll, Professor Emeritus of the University of Mississippi School of Dentistry, USA, and Faculty Consultant at Chiang Mai University Faculty of Dentistry, Thailand, for critical reading of this manuscript. This study was supported by Chiang Mai University research fund.

CT and PP have made substantial contributions to analysis and interpretation of data and in drafting the manuscript. RPA and KP have been involved in drafting the manuscript and revising it critically for important intellectual content and also have given final approval of the version to be published. All authors read and approved the final manuscript.

Choknapa T is a Master student in Center of Excellence for Dental Implantology, Faculty of Dentistry, Chiang Mai University, Thailand. Peraphan P is a researcher in Thailand Excellence Center for Tissue Engineering and Stem Cells, Department of Biochemistry, Faculty of Medicine, Chiang Mai, Thailand. Reichart PA is a professor in Department of Oral Medicine, Dental Radiology and Oral Surgery, Center for Dental, Oral and Maxillary Medicine, Charite – University of Medicine, Berlin, Germany. Khongkhunthian P is an associate professor in Center of Excellence for Dental Implantology, Faculty of Dentistry, Chiang Mai University, Thailand.

Authors Choknapa Tirachaimongkol, Peraphan Pothacharoen, Peter A. Reichart and Pathawee Khongkhunthian states that there are no conflicts of interest.